limit number of thread in ThreadPool while creating TransportClient in elasticsearch

Question

I'm creating a TransportClient instance in elasticsearch. Below is the code for the same. The issue is I'm trying to lower the number of threads spawned with the threadpool that TransportClient initiates. But what ever settings I use my elasticsearch always initialing the threadpool with 12 threads. Please let me know how to configure the same to get the desirable threads.

public static TransportClient getTransportClient(String ip, int port) {

    ImmutableSettings.Builder settings = ImmutableSettings
            .settingsBuilder();
    settings.put("cluster.name", "elasticsearch");
    settings.put("threadpool.bulk.type",  "fixed");
    settings.put("threadpool.bulk.size" ,5);
    settings.put("threadpool.bulk.queue_size", 5);
    settings.put("threadpool.index.type" , "fixed");
    settings.put("threadpool.index.size" , 5);
    settings.put("threadpool.index.queue_size" , 10);
    settings.put("threadpool.search.type",  "fixed");
    settings.put("threadpool.search.size" ,5);
    settings.put("threadpool.search.queue_size", 5);

    settings.build();

    TransportClient instance = new TransportClient(settings)
            .addTransportAddress(new InetSocketTransportAddress(ip, port));

    return instance;
}

Answer 1

Try

Settings settings = ImmutableSettings.settingsBuilder()
                    .put("transport.netty.workerCount",NUM_THREADS)
                    .build();

Credit to JanuZ, taken from http://www.lucidelectricdreams.com/2013/11/reducing-number-of-threads-created-by.html